1. Field of the Invention
The present invention relates to digital cameras, and more particularly to a digital camera adapted to process analogically and digitally an image signal from a CCD using a mosaic-type color filter or a stripe-type color filter, for example, so as to clamp a black level.
2. Description of the Prior Art
There is disclosed one example of a conventional digital video camera of this kind by Japanese Provisional Patent Publication (Kokai) H4-192677 [H04N 5/15, 5/92] laid open to public inspection dated Jul. 10, 1992. This prior art discloses that an analog video signal is analog-clamped and thereafter A/D-converted into a digital signal for being subjected to digital clamping, thereby providing effective utilization of a dynamic range during A/D conversion and keeping constant a quantization level as a tip level of a synchronization signal.
With such conventional techniques, however, there is a fear that noises superposed onto the analog video signal due to analog clamping might have an effect upon digital clamping. Nevertheless, the same publication does not disclose a solving method therefor at all.